


Of Sweet Things

by belovedhypnos



Category: Supernatural
Genre: Alpha Dean, Alpha/Beta/Omega Dynamics, Beta Sam, Bottom Castiel, Claiming, Claiming Bites, Fluff, Getting Together, Human Castiel, Knotting, Light-Hearted, Love Confessions, M/M, Mating Cycles/In Heat, Mpreg, Omega Castiel, Possessive Dean, Self-Lubrication, Smut, Some Humor, Top Dean
Language: English
Status: Completed
Published: 2015-06-22
Updated: 2015-06-22
Packaged: 2018-04-05 16:08:34
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,633
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4186242
Author URL: https://archiveofourown.org/users/belovedhypnos/pseuds/belovedhypnos
Summary: <blockquote class="userstuff">
              <p>Cas becomes human, and Dean enjoys the time the ex-angel is still unpresented. Not Alpha, not Beta, not Omega - just Cas, his clueless, adorable Cas. Cas he has a massive crush on. But nobody stays unpresented forever...</p>
            </blockquote>





	Of Sweet Things

**Author's Note:**

> Just a little bit of light-hearted A/B/O dynamics to brighten up your day. :)

Sam was so engrossed in an article he was reading on his laptop that it he was startled by Cas suddenly standing next to him.

“Jesus, Cas! When did you sneak in here?”

It was incredible: even though Cas had become a human a couple of weeks ago, it seemed he hadn’t lost his ability to just suddenly appear or vanish. He moved quietly as a cat, padding the floors of the bunker softly, dressed in Dean’s old clothes that looked just a tad too big on him. Apart from his habit of sneaking up on people, Cas had changed a lot. He looked smaller, more fragile. His eyes looked even bigger and bluer, his hair even messier than it had been while he was an angel. And there was an air of timid childishness about him. Sam believed that much of it was due to the fact that Cas hadn’t presented yet. Currently, he was no more an alpha than he was a beta or an omega. It was strange: to see a full-grown man who was unpresented. His scent was pure, fresh, and mild. More like clean laundry than anything else.

“I apologize”, Cas said, ducking his head. “I didn’t want to startle you so I approached you slowly. But now I see I failed.” Cas looked genuinely sad about this little failure. Sam raised his eyebrows.

“It’s alright, Cas, don’t worry about it. Is there something on your mind?”

Now that he looked at Cas more closely, he noticed there was something quite unusual about him. He wasn’t dressed in one of Dean’s old plaid shirts: he was wearing a blue dress shirt that looked new and ironed and that _didn’t_ look big on him – it actually fit him. His black jeans were rather tight too, and his hair was combed, or at least gone through an attempt of combing.

“I… I just came to inform you that I’m going out tonight”, Cas said, hesitantly, but he smiled proudly as he had finished the sentence.

Sam blinked. “Oh. OK.”

 _Shit._ Dean was not going to like this.

Ever since Cas had turned human, Dean had become quite… possessive. He wouldn’t let Cas do anything alone. He constantly worried and fussed about Cas: it was quite adorable really. And Cas went along with it, following Dean around like a pet, obeying him and admiring him. It was odd to see Cas going out alone and not having another movie night or cooking lesson with Dean. But Sam guessed it was for the best. It was time Cas learned to be more independent – these weeks had probably just been about easing Cas’ way into humanity. Dean would just have to accept that.

“Is this… good?” Cas asked, looking down at his attire.

“Yeah, you look nice, Cas”, Sam smiled. “Though I think Dean would appreciate it more.” He watched intently the ex-angel’s reaction, and was only a little surprised to see him blushing.

“Really?”

“Definitely”, Sam assured. Cas smiled almost bashfully at the thought of Dean liking his new clothes.

“The jeans are a little bit tight”, he said then, frowning. “I ordered them from the internet. They are maybe a size too small.”

Sam snorted. “Wouldn’t bother Dean, I assure you.”

Cas nodded. “Good.” Noticing Sam staring at him suspiciously, he blushed even deeper shade of red. “I mean… It’s just nice to know that… Uh…”

Sam cracked up laughing.

“You’re going out with _Dean_! Drop it, Cas”, he said as the other man attempted to deny. “So he finally asked you?” He chuckled at the thought of his emotionally constipated alpha brother stuttering out his date invitation.

Cas looked nervous. “He told me not to tell you”, he said worriedly.

Sam rolled his eyes. “I’m so not surprised.”

Right then, Dean marched in, his face flushed right to the tip of his ears. It was clear he had heard the last words of their conversation.

“It’s not a friggin’ _date_ , Sam!” he spat out, causing Sam to have a new laughing fit. “I just… I’m just gonna teach Cas some human things, OK?!”

“No doubt of that”, Sam managed to say before collapsing on the table with laughter.

Dean wasn’t able to make a snarky come-back because he had just turned to Cas and was now apparently having some kind of a stroke. His jaw had dropped, his eyes were wide as they swept over Cas’ body, from head to toe, toe to head.

“ _Wow_ ”, he breathed out, and Sam stopped laughing from the frankness, the undeniable adoration that had taken over his brother. How many times had Dean said ‘wow’ upon seeing another man? This surely was some character development.

Cas almost squirmed under Dean’s stare, bashful and flattered at the same time. “Thank you, Dean.”

Reluctantly Dean seemed to snap out of the spell Cas’ new look had cast on him and managed to speak. “Shall we go?” he asked, smiling gently at Cas, completely forgotten about his little brother.

Sam watched as the two ascended the stairs, Dean – of course – behind Cas. Sam gave him a mental thumbs-up. _Real smooth_ , Dean, he thought. As Cas stopped to open the door, Dean placed his hand on Cas’ waist, and it lingered there even as they disappeared from Sam’s sight. Like the ex-angel couldn’t even walk through a door without help… Sam shook his head slowly. He had known for a while there was something between those two but this was proving out to be even more amusing than he ever thought it could be.

*

“One beer, and – what are you having, Cas?”

Cas examined the long list of drinks at the counter, tilting his head.

“I think I want to try a 'strawberry daiquiri'”, he said slowly.

Dean raised an eyebrow at Cas as the bartender started making the drink. “Really?”

“I like sweet things, Dean”, Cas said defensively.

“Can’t you just… have a beer and stick your finger in it?” Dean said, giving out a nervous laugh at the lame pick-up-line – and _wow_ , why the fuck would he say that in the first place? He fell silent and his face felt hot, but Cas didn’t seem to get it. He just stared at Dean, squinting adorably.

“No, I could not, Dean. I’m not an angel anymore, if you don’t remember. I don’t possess any abilities that could possibly make anything sweeter than it already is.”

“I wouldn’t say that”, Dean said softly, panicking immediately because wow, was he out of control tonight or what? He was grateful that their drinks were ready and Cas seemed to drop the subject as he held his ice-cold, deliciously red drink in his hands.

Dean led Cas to a secluded table in a corner of a cozy pub. Secluded because he had seen how some of the men looked at Cas. He had seen their eyes fixing on Cas’ tight jeans and open collar as soon as they had walked in, clearly appreciating what they were seeing. For some reason it filled Dean with rage, and he wanted to keep Cas as far away from those people as he possibly could.

As they sat down, Dean gripped his pint tight, trying to remain casual and relaxed - and failing spectacularly. Cas looked absolutely stunning, the blue shirt matching his eyes so beautifully it filled Dean’s stomach with butterflies. He couldn’t really blame those guys that were giving Cas the eye – in a way, he was one of them. He felt like a fucking teenager again. He tried not to like it.

They didn’t talk much: after every exchange, a long silence followed, filled with sweet tension. Cas sat close to him, and occasionally his hand or knee would brush against his, the brief touch warm and soft, causing Dean – to his horror – pop a half-boner. _Oh for crying out loud_. He had to get a grip.

Sure, he admitted – to himself at least - that he had been pretty obsessed with Cas for a long time now, and recently he had realized he was also very, _very_ attracted to him. But that didn’t mean that anything apart from a friendship was a good idea, and he was painfully aware of that. That didn’t stop Dean from dreading the day that Cas would present. His worst fears included Cas turning out to be an Alpha and running away from him with some Omega he had knocked up, and Cas being an Omega, leaving the bunker after mating with some thug of an Alpha who Dean already wished to be dead.

Dean wished _this_ could go on forever. Cas being none of those, Cas being… just Cas. _His_ Cas.

“So, um… which human things would you like to learn tonight?” Dean asked, shifting awkwardly at his seat, hoping the state of his groin wasn’t completely obvious. “Hustling pool, maybe? A new card game?”

Cas looked thoughtful as he licked the strawberry daiquiri off his lips. “To be honest… I would like to get more experience of kissing.”

Dean choked on his beer. “W-what?”

Cas smiled at him bashfully. “It is one of my favorite human things.”

“Well…”, Dean said, his heart racing, “I guess we’ll just have to find you a kissing partner then.” It was a joke, but uttering those words made him feel sick. Just the thought of anyone else kissing Cas, even touching Cas, made him sick. And he didn’t really want to contemplate why.

“I think I’ve already found someone I’d like to teach me”, Cas said, almost shyly.

“Oh, really?” Dean felt his chest swell with uncontainable emotions. He felt shaky and out of breath, and had to take a long swig of beer in order to calm down a little.

“Yes. I’m just not entirely sure if he finds the idea of kissing me appealing.” Cas seemed hesitant now, staring at his drink and avoiding Dean’s eyes.

“I think he finds the idea very, very appealing”, Dean said. His own voice sounded distant in his ears; he was feeling dizzy and unreal. He couldn’t believe that this was happening, that they were talking about this. But now that the chance had appeared, he damn sure would make sure that he’d have Cas, even if it was just for one night - hell, even if it was just for one kiss. Even if this really was just some confused desire of the newly human Cas, a passing fancy, a light-hearted experiment, Dean would take anything he’d get.

Cas turned to look at him, his eyes full of hope and joy. But the ex-angel didn’t do anything – he didn’t move an inch closer. Dean realized that he was _waiting_. So, he draped an arm around Cas’ narrow waist, gently pulling him closer. He felt like drowning into the blue of Cas’ eyes, he closed his eyes, and then – the soft warmth of Cas’ mouth met his lips, and he felt his heart skip a beat or two. It was _so good_. It was slow and gentle but intense. Dean felt Cas melt into the kiss, responding eagerly, and the sensation of Cas’ perfect lips against his made his legs weak and his jeans tight.

The kiss turned more and more passionate, and Cas draped his arms around Dean’s back, pressing himself close against Dean, deepening the kiss. After a while Dean felt he was losing control. He felt… fuck, _he felt like an alpha_. Reluctantly, he pulled away.

“Y-you’re good”, he panted, his face hot and the front of his jeans tenting up with a raging boner he wasn’t even trying to hide anymore. Cas leaned against him, staring up at him with those gorgeous, blue eyes Dean could never say no to. “You wanna practice more?” Dean said, throwing all rationality he had left out of the window. Cas nodded eagerly, and Dean leaned in for another kiss.

This time it was fervent, sloppy, out of control. Cas moaned softly, a sound that made Dean almost come in his pants. At that moment Dean wouldn’t have cared if they were sitting in the middle of the pub and all of the other guys’ eyes were on Cas: _he_ was the one making out with him, and he felt a surge of pride inside of him, hoping that everybody was looking.

Suddenly Cas seemed to resist, trying to pull away. Dean wouldn’t let him. He squished Cas against the booth wall, kissing him hard and demanding. He had never before noticed how amazing Cas smelled: sweet and warm, like honey and fudge and with a hint of cinnamon and something there were no words for… It was almost like Cas was…

“Dean!” Cas gasped as he managed to pull away enough to speak. Dean stared at him, panting. “I’m… wet.”

“What?” Dean mumbled.

Cas’ hand was shaking as he took Dean’s hand and led it to the back of his jeans. Dean swallowed hard as he felt the fabric indeed to be soaking wet.

“Cas… you’re an Omega.” Cas stared at him, eyes wide. “You’re… you’re _in heat_.”

A realization spread over Cas’ face. His chest was heaving, his cheeks flushed, and his scent grew stronger and more irresistible every second. Dean cursed under his breath. He realized now why Cas had suddenly started to smell so amazing to him. Cas had started to present in the middle of their make-out session - and went immediately into heat.

_Dean was so screwed._

“Cas…” Dean said, looking away, trying not to let Cas’ scent infiltrate every cell of his body. ”I know what you’re probably thinking, and… it’s not a good idea.”

“Dean”, Cas said, his voice pleading. “I want you. _I love you_.”

Dean felt a sudden panic rising within himself. “Oh for fuck’s sake! You don’t love me, Cas, you’re just in heat!”

Cas took his hand and brought it to his lips, kissing his fingers. “I’ve always loved you, Dean. And I... I believe that is why I presented as an Omega. I love you like an Omega loves his Alpha.” Cas’ voice was so passionate, his eyes so adoring, that Dean felt his resistance crumbling. “ _Claim me_ ”, the Omega said, his voice half-whisper, half-whine.

“I love you too”, Dean said, his eyes filling with tears at the realization of how true those words were - how long they had been true but unspoken. He took a deep breath. “But Cas… you have to realize… if we do this, you’re stuck with me. For the rest of your life.”

“I want to be stuck with you, Dean”, Cas mumbled, leaning in to kiss the hunter’s neck.

That was it. Dean couldn’t fight it anymore. He grabbed Cas by the wrist and led him out of the pub.

*

By the time Cas was lying on his back on the back seat of the Impala, Dean didn’t care about anything anymore - anything but being inside Cas. He didn’t care about all the other cars on the parking lot, or all the fears he had about himself when it came to romantic relationships; all the resistance had left him, all the common sense he liked to apply to situations like this was long gone. What was left in him was the mighty need to claim, to make Cas his, to fill him, hell, maybe even knock him up with a pup or two. As long as it included his cock buried deep inside Cas, he was all for it.

Dean had quickly deprived Cas of his clothes, and with shaking hands freed his own painfully hard erection from the confinement of his jeans. Cas whined softly as he spread his legs for Dean. Dean needed no further invitation. He placed himself on top of Cas, pressing against his hot skin, his cock finding its way to the slick hole in between Cas’ legs. His hips made an almost involuntary movement, causing the tip of his cock slide past Cas’ rim. Cas moaned loudly, his whole body tensing up and his hips pushing up against Dean’s, urging him deeper. Dean groaned, bottoming out in the irresistibly tight heat of Cas’ body. He made sure Cas didn’t need to plead anymore: he set a steady, fast rhythm, angling his hips so that he could thrust as deep as possible. Cas clutched at the leather of the backseat, squirming and moaning underneath Dean.

“Mmmmhhh, fee-eels so-oo goo-oood”, Cas moaned, releasing a gush of slick on Dean’s cock, making penetration even more effortless, producing filthy, wet sounds with every thrust.

“ _Fuck_ ”, Dean groaned. He felt his cock throbbing – he knew he wouldn’t last long. Part of him never wanted this to be over, but even bigger part of him wanted to knot Cas as soon as possible.

He made a few slower thrusts, Cas’ tightness massaging his length in an almost intolerable way. Staring down at his mate, he met lust-darkened eyes staring up at him in awe, once deep blue, now almost black; face flushed bright pink, and swollen, parted lips. Dean felt the tell-tale churning in the pit of his stomach, the tingling in his balls, and a low growl rumbled in his throat. The Omega tilted his head, exposing his neck for his Alpha. Dean eagerly leaned down to pierce the soft skin with his teeth, Cas’ blood tasting sweet as honey to him. With one final, deep thrust he came inside the welcoming body underneath him. He squeezed his eyes shut, holding onto Cas like his life depended on it, only barely registering Cas’ whimpering in his ear.

When he came around, regaining his senses, he realized he was knotted balls deep inside Cas, the Omega practically purring under him. The rationality he had so voluntarily thrown away quickly returned to him.

_Shit._

His brain made a quick wrap-up of the situation: _You have mated your best friend, a former angel of the Lord, and done it without any kind of contraception. Congratulations!_  He could almost hear the cheering and applauding. Fuck.

“Cas? You OK?” he asked, pushing himself up on his elbows so he could see Cas’ face. Cas smiled at him, his eyes bright.

“Yes, Dean. How are you?”

Gosh this was awkward. This was like one of their most common exchanges, but the context was just... _slightly_ different.

“I’m… I’m good”, Dean said. Which was really an understatement – he had just had the most intense orgasm of his life. And judging by the mess on Cas’ chest, so had the ex-angel. He grabbed Cas’ waist and turned them so that both of them were lying on their sides. They were just blinking at each other, looking content but a little lost.

“I’m just a little worried”, Dean said after a while, even though he didn’t really want to talk about it. But one of them had to.

“Why?” Cas said sleepily.

“You know why”, Dean said a little impatiently. “Come on, Cas, you could get pregnant.” He looked away, a blush of shame coming over his face. _And it would be my fault. I didn’t care. I just had to have you._

Cas only smiled. “So?”

Dean raised his eyebrows. “You wanna have a baby?” he asked incredulously.

“Yes, Dean”, Cas said softly. “It’s yours, so of course I want it.”

“OK, now you sound like there already is a baby”, Dean said, a mild panic in his voice.

“There might be”, Cas said, closing his eyes. But the smile still stayed on his lips. “And if there is, I want it.”

Dean swallowed hard. Underneath the panic, he felt the same way. He’d love anything Cas could give him.

He wrapped his arms around Cas, pressing a kiss on his forehead.

“I guess we’ll just have to wait and see.”

Cas had already dozed off. Dean shook his head, a fond smile on his lips. If there was one person who could be so calm about turning into another species and the prospect of being pregnant after two weeks of being a member of said species, that was Cas. His brave, patient, amazing Cas. His very own Omega.

*

Soon after their mating, Dean’s panic dissipated. Only in a couple of days, he found himself _hoping_ Cas would be pregnant. He wanted a more clear proof that Cas was his, and his pup growing inside Cas would be it. He didn’t dare to express this hope, though: he only anxiously waited for the Omega to start displaying the tell-tale signs or for his scent to change (even though that wouldn't probably happen until later on): something that would confirm that he was going to be a father. He wanted to appear as the rational one – he wanted to emphasize all the practical problems a child could bring into their lives, the fact that hunting wasn’t a lifestyle for parents, and so on. Yet, he liked to imagine Cas’ sleepiness and headaches as symptoms of pregnancy, and he couldn’t have been happier when Cas had his first morning sickness. He took the Omega to the doctor right away, pretending to be concerned about the possibility of Cas having some vicious illness.

That day it was confirmed that Cas was indeed three weeks pregnant.

Sam wasn’t at all surprised to find out that his brother and their friend had mated and that he was soon to become an uncle. He was only glad he didn’t have to witness them dancing around each other anymore, and thrilled to have a little niece or nephew. He was just a little sad that no longer would he get to laugh at Dean’s one-man show called _“I’m not in love with Cas”._

Also, now he had to witness Dean being gross around the clock and spoiling Cas rotten.

Oh well. It seemed happiness always came with a price.


End file.
